What are the structures on chromosomes that carry inherited characteristics called?

The structures on chromosomes that carry inherited characteristics are called genes. Genes are specific sequences of nucleotides in DNA that code for proteins, which in turn influence an organism’s traits and characteristics. Each gene occupies a specific location on a chromosome and can vary in terms of expression, which ultimately contributes to the diversity seen in traits among individuals.

In the context of genetics, while chromatids refer to the two identical halves of a duplicated chromosome, they themselves do not carry the inherited information; rather, they are part of the chromosome structure during cell division. The term genome encompasses all of an organism's genetic material, including all genes, but it does not specifically refer to the individual units that carry inheritance. Chromosomes are the structures that hold genes, but the focus of the question specifically pertains to the fundamental units that encode inherited characteristics, which are indeed the genes.